1. Technical Field of the Invention
The present invention generally relates to a differential assembly. More specifically, the present invention relates to the novel manner in which the ring gear is attached to the differential housing.
2. Description of the Prior Art
In an automotive vehicle, a differential gear assembly is used to transfer power from a rotating driveshaft to the axles and wheels of the vehicle. The rotating driveshaft of the vehicle engages a ring gear which is mounted onto a differential housing. The end of the driveshaft and the ring gear are adapted to transfer rotation from the drive shaft to the differential housing such that the differential housing rotates transverse to the driveshaft. Within the differential housing, the ends of the axles of the automobile are supported and connected to the differential housing through a differential gear set, such as a bevel differential gear set. Thus, the ring gear of the differential housing allows the driveshaft to rotate the differential housing in a direction transverse to the driveshaft, whereby the differential gear set rotates the axles of the vehicle to drive the wheels of the vehicle.
Typically the differential housing includes a flange extending around an outer diameter of the differential housing. Currently, the most common method of attaching the ring gear to the differential housing is by drilling and tapping a plurality of holes within the flange and bolting the ring gear to the flange. The differential housing and the ring gear must be structurally sound enough to withstand the localized stresses at the tapped holes and to maintain their overall strength. To accomplish this, the ring gear and the differential housing must be thick and large. This adds size and weight to the differential gear assembly.
As seen from the above, there is a need to improve the structural integrity of a differential gear assembly while also decreasing weight.
It is therefore an object of this invention to provide a differential gear assembly with a differential housing and a ring gear having features which allow the ring gear to be attached to the differential housing without compromising the structural integrity of the differential housing or the ring gear while also reducing the weight of the assembly.
The disadvantages of the prior art are overcome by providing a differential gear assembly, in accordance with the present invention, in which the ring gear is attached to the differential housing in a manner that does not compromise the structural integrity of the differential housing or the ring gear.
In a first aspect of the present invention, the differential gear assembly includes a differential housing, a gear set mounted therein (which is typical of such differential gear assemblies) and a ring gear mounted externally to the differential housing and held thereto by a clamp. One advantage of the present invention is that the ring gear is not secured to the differential housing by bolts. Therefore, no drilled or tapped holes are formed within the ring gear or the differential housing. The ring gear and the differential housing can be designed without compensating for weaknesses in the structure due to the drilled and tapped holes, which are typical in prior art differential gear assemblies.
In another aspect of the present invention, the differential housing and the ring gear each include an annular flange and the clamp includes a pocket which is adapted to receive the annular flanges to secure the ring gear onto the differential housing.
In still another aspect of the present invention, the differential housing includes a pinion pin secured to and extending diametrically across the ring gear. The ring gear includes features that receive the ends of the pinion pin whereby load is transferred from the ring gear directly to the pinion pin.
In yet another aspect of the present invention, the flanges of the differential housing and the ring gear are formed with opposing angled surfaces and the pocket within the clamp includes a bottom and opposing angled sides. When the clamp is placed to the flanges, the angled surfaces of the flanges engage the angled sides of the clamp such that the clamp provides an axial clamping force to the flanges.